Something I thought would be a no-brainier has turned into frustration. I'm reinstalling the tins, heat exchangers and ducting and ran into a fit problem. Doesn't seem that others have had the problem because my research came up empty.

What is the sequence of installation? Heat exchanger first or the duct piece first?
Thanks, Jack
This piece:
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Jack, heat exchangers first, then the piece in your pic, then the j tube, then branch tube, then heater valve. It can be tricky, but it will go. Don't forget the small flaps that hang from the fan shroud openings.

Btw, your
shims were taken to the post office this afternoon.

Thanks very much Curt!

What do the flaps do? Mine are missing.

Also, my square duct covers don't fit very well?

The flaps will keep the aux blower fan from pushing air from the exchanger back into the fan shroud.

The square covers, if I understand what you mean, are unique from side to side. Try swapping them and see if they fit better.

--DD

If you're not using the aux heater blower, then these little flappers are not needed.
Well, that's my plan anyway.

Before installing, do a trial fit of all the parts on the bench.
Especially the tubes and valves.
Make certain the tubes can properly enter the valves.

Is the aux blower feature really needed?

No, not really. It's real purpose is to force air through the HE's when the engine speed isn't high enough to do so (e.g., while idling). If you don't put the aux blower on then it's been recommended you cap the J-tubes on each left/right engine shelf to prevent hot air making it's way up into the engine bay. That's they way I'm running right now.

Plus, lack of the 2 doors on the shroud and uncapped j tubes makes for poor heating. REALLY poor. The heat system delivers when the design components are serviceable and in place.

Would you get better engine cooling by blocking the fan shroud flaps, and just relying on the aux blower for all the air, and using the motor fan just for motor cooling?

Take lots of pics and notes. I am a few steps behind you. :-)